$('#slideshow').slideshownav({
transition: 'push(#{direction})',
mode: 'vertical',
navSelector: '> ul > li > a',
duration: 400,
autoPlay: false
});
The slideshownav widget extends slideshow by attaching click events to navigation elements. Note the #{direction} transition "variable". Depending upon the previous and next slide indices and the instance's options.mode, the direction becomes "left", "right", "up", or "down".